After two years of delays because of problems with a seismometer instrument, NASA’s InSight Mission apparently has successfully landed on Mars today to explore the deep interior of the planet, about which scientists know little.
Oregon State University atmospheric scientists assisted with the planning for the two-year Insight mission, which will dovetail into a larger and more complex mission in 2020, when NASA launches another craft that will explore the Red Planet looking for signs of life.
Oregon State University atmospheric scientist Jeffrey Barnes has been working on both missions, helping the NASA engineers and scientists determine the best locations for landing. Just last week, NASA chose the Jezero Crater for the 2020 landing spot from an original long list of contenders.
InSight is expected to land today at Elysium Planitia, which often has been called the “biggest parking lot on Mars” because it is open and flat. The winds at this location are relatively weak according to atmospheric modeling, Barnes said, and this is critical for the success of the seismometer.
Temperatures on Mars can fall below minus-200 degrees Fahrenheit and winds are often 50- to 60-miles-per-hour at the surface, and as high as 400-mph in the upper atmosphere. Of bigger concern, though, are dust storms.
“The 2020 landing season on Mars – in the very early northern spring – is very favorable to landing near the equator,” Barnes said. “The InSight Mission, which we’ve worked on for four years, has a much more challenging season – the northern winter, which is the heart of the dust storm season. And the spacecraft is not nearly as capable for EDL (entry, descent and landing) as the craft in 2020 will be.
“But it now appears that Mars is cooperating as the very intense global dust storm that began back in June has finally begun to die down. The atmosphere is still fairly dusty, but not much above normal conditions at this season on Mars.”
Barnes has focused most of his career on studying the atmosphere of Mars. He and his colleagues have been running computer models of the weather on Mars to help NASA engineers determine the best locations and strategies for landing crafts for both the InSight and Mars 2020 missions.
Though the locations and crafts differ, the basic challenge is the same: How can you slow down a craft hurtling into a very thin atmosphere and land it softly on the surface of Mars some 35 million miles away? It takes radio signals 10-15 minutes to travel between Mars and Earth, so everything has to be commanded by the spacecraft’s computer.
“The biggest key is atmospheric density, which depends upon both temperature and pressure,” Barnes said. “At high elevations, the density is much lower, making it more difficult to slow and land a craft. That’s one reason why the last mission, the Mars Science Laboratory with its Curiosity rover, landed in Gale Crater in 2012. Going down an extra 3-4 kilometers buys you a lot of margin for error.
“The atmospheric winds are also of considerable importance for the EDL phase of the missions.”
Barnes and colleague Dan Tyler have been working with NASA’s Jet Propulsion Laboratory on both the 2018 Mars InSight mission and the Mars 2020 mission. InSight – an acronym for “Interior exploration using Seismic Investigations, Geodesy and Heat Transport” – will place a lander on Mars equipped with a sophisticated seismic instrument designed to provide information about Mars’ deep interior.
For both of these projects, NASA utilized two parallel atmospheric modeling teams – one from Oregon State and the other from the Southwest Research Institute in Boulder, Colorado. The dual approach provides different perspectives of the same problems, Barnes noted. A French group also provided modeling results for the InSight mission.
“Most of the time, we were in pretty good agreement on our calculations,” he said, “but sometimes we were not and that makes us both go back and take a closer look at our models and assumptions.”
The model of the Mars atmosphere created by Barnes and Tyler has very high horizontal resolution. Their mesoscale model simulates the Mars atmosphere using horizontal grids with a spacing of 3-5 kilometers and the grids can be made as fine as 1-2 kilometers.
Barnes and Tyler also worked on the NASA Phoenix mission, which landed in the north polar region of Mars in 2008, as well as the Mars Science Laboratory mission that landed in 2012. That mission, like InSight, also suffered a two-year launch delay. Barnes’ involvement in Mars research dates back to the Viking mission in the 1970s that landed two spacecraft on the surface and put two others into orbit around Mars.
He also was a science team member on the 1997 Mars Pathfinder mission, which operated the first rover on the Mars surface.